The 1828C from Electro-Voice is a commercial sound compression driver is a 30-watt, heavy-duty, convertible driver designed for use with compound-diffraction horns designed for general public address applications. The drivers have rugged phenolic diaphragms, 1.5 inch diameter voice coils and "rim centered" ferrite magnet structures for long life and reliability under extreme operating conditions. The exterior is finished in durable waterproof paint and all metal parts have been treated for resistance to high humidity and fungus. Ideal for both indoor and outdoor applications, these drivers are well suited for any installation requiring rugged and reliable performance.